Data storage devices store digitally encoded information on discs. Heads read data from or write data to discs which are supported for rotation relative to a base chassis by a spindle motor or drive. Heads include transducer elements, such as magnetoresistive, magneto-optical or inductive elements for read or write operations. An actuator assembly moves the heads relative to select data tracks on the disc for read or write operations.
Typically the head includes a slider having an air bearing surface which is coupled to a head suspension assembly. Rotation of the disc creates an air flow along the air bearing surface of the slider to provide a lift force. The lift force of the air bearing surface is countered by a load force supplied via the suspension assembly to define in part a fly height Hfly of the slider relative to the disc surface. The slider is coupled to the head suspension assembly via a gimbal spring so that the slider pitches and rolls to follow the topography of the disc surface. The slider generally flies at a pitch angle so that a trailing edge or portion of the slider or head defines a close point of the head relative to the disc surface. The fly height Hfly of the trailing edge is generally above a glide avalanche height of the disc to limit slider-disc contact.
The fly height Hfly parameters of the head effect spacing between the transducer elements of the head and a magnetic or data layer of the disc. Following a “warm up period” increases in ambient temperature of the device and heat generated via write current can cause thermal expansion of the transducer portion (or pole tip protrusion) of the head relative to the slider body. Thermal expansion of the transducer portion provides a smaller separation between the transducer elements and the recording media. Prior to a “warm up” period and thermal expansion, the spacing between the transducer element or elements and the recording media may be too large for effecting writing on the first few sectors interfering with write operations. Energization of a heating element heats the transducer portion to limit interference with write operations prior to the “warm up” period.
Transducer elements of the head are typically embedded in an Alumina Al2O3 or other materials. Ambient moisture or condensation of ambient moisture can corrode or damage the transducer elements or portion of the head. Prior head designs include a diamond-like carbon layer or protective layer deposited on the transducer or portion to protect the transducer portion or elements from corrosion or wear. The protective layer increases the spacing between the transducer element or elements and the media relative to the fly height of the head or slider. Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.